Right, standard I'm not a lawyer disclaimer but here is my interpretation.

Anyone trading bitcoins for fiat with another person is a money transmitter regardless of amount or frequency (though perhaps not if they are using a licensed exchange who takes on the role of MSB). All money transmitters are MSBs. All MSBs have to register and are then subject to expensive fees and regulatory practices by their states.

I would like a lawyer to explain why this interpretation by FinCEN is legal

It does not make sense to me that I grew carrots and sold them I would be a farmer, but if I mined bitcoins and sold them, or earned in game Diablo gold and sold it, or earned second life dollars and sold them, that I would now be subject to extremely expensive regulation.

Apparently anyone selling any type of virtual currency on ebay or craiglist is now a money transmitter, and as such a MSB, and as such now in violation of FinCEN interpretation if they haven't registered as an MSB.

There has to be some lawyer out there who is interested in Bitcoins and who can offer their interpretation on this matter.